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New upper limits for H particle production in anti-p Xe annihilation at low-energy

Barmin, V.V. ; Barylov, V.G. ; Chernukha, S.F. ; et al.

Phys.Lett.B 370 (1996) 233-238, 1996.

Inspire Record 429472 DOI 10.17182/hepdata.28391

A study of the reactions p Xe → K + K + X , p Xe → K + H(H → Σ − p)X and p Xe → K + K + H(H → Σ − p)X was performed using the 700-litre xenon bubble chamber DIANA, exposed to the 1 GeV/ c antiproton beam of ITEP (Moscow). From a sample of 7.8 · 10 5 antiproton annihilations at low energy in xenon nuclei 4 events were observed for the reaction p Xe | → K + K + X at rest ( P p ≤ 400 MeV /c ) and 8 for the same reaction in flight ( 400 ≤ P p ≤ 900 MeV /c ). The corresponding probabilities turned out to be 3.1 · 10 −5 and 3.4 · 10 −5 , respectively. No H -event was found in the two semi-inclusive reactions p Xe → K + HX and p Xe → K + K + HX . This lead to the upper limits 6 · 10 −6 and 8 · 10 −6 (90% C.L.), respectively. The corresponding upper limit for the fully inclusive reaction p Xe → HX turned out to be 1.2 · 10 −5 (90% C.L.), which is about one order of magnitude lower than the actual value reported in the literature.

1 data table

Table 1

No description provided.

Observation of subthreshold double strangeness production in anti-p annihilations on Xe nuclei: Search for stable H dibaryon

The Diana collaboration Barmin, V.V. ; Barylov, V.G. ; Chernukha, S.F. ; et al.

Nucl.Phys.A 558 (1993) 361C-368C, 1993.

Inspire Record 358877 DOI 10.17182/hepdata.20612

The double strangeness production has been observed in two final states of annihilation of antiprotons at momentum less than 0.9 GeV/ c on Xe nuclei: K + K + X (8 events) and K + K 0 ΛX (6 events). The probabilities of the reaction p Xe → K + K + X vary from 2 · 10 −5 (at rest) up to 7 · 10 −5 (in flight). The reaction p Xe → K + K 0 ΛX is observed only in flight with probability 3 · 10 −4 . The properties of the observed reactions are similar to those resulting from the cascade process with production of Ξ hyperon: p N → K ∗ −K ∗ , K ∗ → Kπ, −K ∗ N → ΞK, ΞN → ΛΛ . The new upper limit on the production probability of the stable H ( S = −2) dibaryon in the reaction Xe → K + K + H(H → Σ − p)X was obtained to be < 2 · 10 − (90% C . L .).

1 data table

Table 1

No description provided.

Anti-proton He-4 interactions at 200-MeV/c

Balestra, F. ; Batusov, Yu.A. ; Bendiscioli, G. ; et al.

Phys.Lett.B 305 (1993) 18-22, 1993.

Inspire Record 362745 DOI 10.17182/hepdata.28940

The differential cross sections for antiproton elastic scattering on 4 He at 192.8 MeV/ c are measured. The annihilation cross section σ a = (377.6 ± 8.0) mb, the elastic cross section σ el = (206.3 ± 6.6) mb and the total p 4 He interaction cross section σ tot = (583.9 ± 10.4) mb are determined. The ratio of the real to imaginary part of the forward p 4 He amplitude is found: π =−0.17± 0.33 0.24 . Partial wave analysis reveals that the S, P and D waves are essential in this energy region.

7 data tables

Table 1

Charged prong multiplicity distributions in pbar HE annihilation.

Table 2

Mean charged particle multiplicity in pbar HE4 annihilations.

Table 3

No description provided.